Our two year stretch of little to no blast might be over. I visited an M-209 field last week that seemed to be infected with blast. The lesions appeared to me like propanil drift burn; however, the yellow halo around the lesions made the PCA suspicious. Paul Sanchez, pathologist at the Rice Experiment Station, collected some leaf samples and was able to confirm it is blast.
According to Paul, changes in environmental conditions may be why the lesions did not look like your typical blast lesions. When conditions are favorable, the fungus' spores germinate and infect the tissue. But if conditions change and become unfavorable for the fungus growth and sporulation, the fungus dies and the tissue then has that burned look instead of the white-gray powdery look.
Some of the lesions did look more like the typical blast lesion.
M-209 is a variety closely related to M-205, a variety considered to be susceptible to blast. Since we have not seen blast in the field since M-209 was released, we do not know what level of susceptibility M-209 has. This might be the year we find out.
At this point, a fungicide treatment is not recommended. However, a treatment near heading may be appropriate considering that the field and area have a history of blast epidemics./table>
This year, armyworm infestations were not as severe as last year. Populations did not reach the very high numbers of 2015, but they were early. Growers and PCAs were scouting diligently, and were able to recognize infestations when the worms were small. This gave growers the upper hand and many were ready to make a treatment decision if necessary. Intrepid was used in some fields successfully.
We are not totally off the hook yet. We usually get a second peak of armyworm activity during the late boot and heading stages. UCCE is monitoring moth populations in several areas of the valley using pheromone traps. The traps were set up in early July, and the trapping numbers will be shared in this blog and the UC Rice On-line website.
So far, moth numbers are low, averaging 2.5 moths/trap/day during the week of July 11. Numbers have decreased since the previous week, when the average was 4.3 moths/trap/day. The location with the highest moth numbers is near Knights Landing, averaging 9.2 moths/trap/day. Previous work done by Larry Godfrey, UC Davis Extension Entomologist, found that peaks of 20-40 moths/trap/day might indicate an armyworm larvae peak 7 to 10 days later.
Number of moths/trap/day captured in armyworm pheromone traps across the Sacramento Valley
Whitney Brim-DeForest is the newest addition to the UC Cooperative Extension Farm Advisor rice team. She will be based out of the Sutter-Yuba Office, but will serve Placer and Sacramento counties as well. She holds a Ph.D. in Horticulture and Agronomy and an M.S. in International Agricultural Development (both from UC Davis), and a double B.A. in Biology and Music from Brown University. Before starting her graduate work, she served as a Peace Corps Volunteer in Senegal, West Africa, for three years, where she worked with growers in a variety of crops, including rice, sorghum, corn, and cowpeas. Since 2012, she has worked at the Rice Experiment Station in Biggs, CA, managing the field trials for the UC Weed Science program in rice.
Why do you want to work in Cooperative Extension?
I really enjoy being out and about in the field, talking to growers and PCA's. I prefer doing research that can have an immediate impact, that results in new tools and information that growers' can use in their own fields. I find that I learn a lot from growers' and PCA's, as they are in the fields every day, and are often the best at identifying the potential implications of a research idea--the risks and benefits to growers.
What is your background?
I am a weed scientist by training, and so far, my research has been primarily focused on weed agroecology: the interaction of weeds with the rice field environment. Since I started at UC Davis, I worked first with Dr. Albert Fischer and then with Dr. Kassim Al-Khatib at the Rice Experiment Station (RES) in Biggs, where I managed the weed science field trials. During my time at the RES, through the herbicide-resistant weed testing program, I met many growers and PCA's and I am looking forward to meeting more of you!
Weed control plots at the annual Rice Field Day at the California Rice Experiment Station in Biggs, CA.
What are your research and outreach plans for the future?
This season, I plan to spend time getting to know Sutter, Yuba, Placer and Sacramento growers and PCA's, and to familiarize myself with the location of your farms, fields, and places of work. I'm looking forward to meeting as many of you as possible, so that I can begin understanding the issues that you identify as the most important.
Some of my future outreach ideas include a rice-specific workshop on weed management and identification and some videos on weed identification and seed collection. With the other farm advisors, I will be involved in research on the emerging weed issues, including red rice and the winged primrose willow. Currently, I am involved in research focusing on identifying and managing herbicide resistance, since that is a concern for many rice growers. Over the next 1 to 2 years, this will include surveying and screening for resistant populations in growers' fields.
Feel free to contact me at any time, at the Sutter-Yuba Office, at 530-822-7515, on my cell at 541-292-1553, or by email at firstname.lastname@example.org
Close-up of ducksalad emerging in the greenhouse/table>
- Author: Bruce Linquist
Do you think you have a good looking field of rice? Do you wonder how it might stack up against other fields? Well then join the 2016 UCCE Rice Yield Contest. This year we are expanding Yield Contest from Butte County to the whole Sacramento Valley. We have divided the valley into four regions (using Hwy 20 and the Sacramento River –see rules for more details) so you are competing with growers in the same general area.
However, to join you must do so before Aug 1 by filling out the entry form and send it back to us. Please make sure you read the rules (http://rice.ucanr.edu/files/239587.pdf) before entering the contest. If you have questions please feel free to give us a call.
If you want to find out about last year's winners, go here.
Before the weekend I got reports of two fields where defoliation was over threshold and worms were big. As predicted, we are now seeing armyworms at fifth and sixth instar. These are the worms that will cause noticeable defoliation. The timing of infestation is similar to last year's.
I scouted a field in Colusa on Friday. Defoliation was limited to corners, and even though it was over threshold at some spots, the field was not at risk. However, it is important to keep scouting because there are still small worms that will continue to develop and can potentially cause more defoliation.
Intrepid is not available for use yet. Hopefully we will be hearing from EPA and DPR soon.
I also noticed a heavy infestation of caterpillars on the cattails. I don't know what these caterpillars are, but they are not armyworms. The cattails were heavily damaged, but not the rice. There were several of these caterpillars resting on rice, but they were causing very little defoliation. I suspect these are Simyra insularis, the cattail caterpillar (very appropriate name).